[gDesklets] Proposal in the loading process

[mgonzalez mandriva com]

Hello:

I use a startup script to launch several desklets. But if the loading
process in more than 1 desklet fails, I don't want to have several
gtk.Window() telling me there are some mistakes in some XML files.

I wrote a patch to give the ability to make a decision if gdesklets just
needs to write a message to the log or show a popup instead.

Regards.